Abstract:
Additive Manufacturing (AM) is presently revolutionising industrial production in many sectors (Aerospace, Automotive, PowerGen, Oil&Gas, Medical, etc.) and is expected to substantially substitute traditional moulding and casting processes within the next decade to come. For many workpieces made of plastic and metal based materials, AM tends to be the more convenient manufacturing technique due to their complexity and geometry.
Apart from other known non-destructive techniques to assure quality of AM products such as e.g. in-situ monitoring during the build process, computed tomography (CT) turns out to be one of the most efficient NDT methods. Not only does CT enable the three-dimensional volumetric visualization of indications and internal geometries that traditional NDT methods can scarcely or not access, it also allows to be used for metrology application tasks, such as dimensional measurement of interior and exterior features, variance analyses (CAD data, part-to-part) and pre-machining workpiece control.
Moreover, CT may help analyse the granulometry, topology and sphericity of AM powder particles (new/recycled) to assure quality of the incoming material prior to the printing process.
In view of new types of defects and flaws to be detected in AM parts, CT can meet requirements for increased resolution, higher penetrability and X-ray scatter-corrected volume data sets of workpieces made of dense materials (e.g. Inconel, CoCr, etc.) allowing for reliable and reproducible measurement results. Thanks to this and to improved automatic workflows, CT continues its move from being a traditional expert R&D device towards the use as an automatic measurement technique on or close to the production floor.
Computed tomography can help to set standards for quality assurance of AM parts. Hence, standardisation organisations such as ISO and ASTM rely on the recommendations and the expertise of CT system suppliers and CT users among the AM community members.
Keywords:
Additive Manufacturing, AM, Computed Tomography, CT, 3D Visualisation, Metrology, Standardisation ISO/ASTM.

As the complexity of aerospace components and manufacturing processes continue to increase, so does the need to move beyond the capabilities of traditional inspection methods, such as 2D radiography and ultrasound. Computed tomography (CT) enables the visualization of indications and internal geometries that traditional methods cannot.
Visualization of indications and internal features using CT has been utilized in research and development environments for years, however has rarely been used as a production tool, especially in casting environments. Inspection speed, image quality of dense parts, data workflow, operator visualization and training have been some of the challenges to bringing the benefits of this technology to casting manufacturing. As the need for CT in the factory environment increases, so has the pressure on the industry and technology providers to solve some of these big challenges.
Over the past year, giant leaps in CT technology have resulted from the increased pressure and industry collaboration to close the gaps and move closer to implementation in casting environments. Technology improvements have been realized to increase volumetric data collection by factors of over 10x, while maintaining and even improving image quality. System and data workflows have been modified from traditional expert R&D use cases to now allow for production workflows with various user levels and enabled DICONDE data management. CT training courses have also been developed to assist in the training and certification of operators.
Keywords:
Data Management, DICONDE, Radiography, CT, Productivity, Image Quality, Workflow, 3D Visualization, Training

More and more typical radiographic applications get converted into digital solutions. Due to the similarities to traditional film methods in setup and handling, one of the most favored conversion technologies are Computed Radiography systems. The quality of these systems and the comparability to radiographic exposures has long been discussed, and the trade between spatial properties and contrast resolution differences has led to new specifications and standards measuring the system performance and quality.
GE Inspection Technologies as part of GE Measurement & Control understands their NDT business as Healthcare for Industry. In this spirit we have driven the digital conversion from the start, and are as a leader in this process constantly sharing our experience, progress, recommendation and outlook. One of the essentials to a save and transparent conversion is to understand the differences in technology, the drawbacks and advantages, but also to understand how to work with the new relevant standards for this technology when it comes to weld applications. This paper will make the effort to walk you through the most important steps of Film to Digital conversion for weld.

Computed Tomography (CT) has evolved into an established industrial testing procedure. In addition methods apply, which extend the use of CT for 3D metrology purposes. Within this development, a VDI/VDE (Association of German Engineers) guideline has been defined, which describes how a CT system for use in 3D metrology can be qualified.
Applying the VDI/VDE directive on a typical system CT, initially geometric parameters such as length deviation and probing deviation have been determined. A study how important system components such as X-ray tube, detector or manipulator influence the parameters shows optimization potential. In particular the correction of detector and manipulation system is interesting. Finally, the increase of measuring overall performance of the CT system will be demonstrated.

Industrial computed tomography (CT) enables the non-destructive and 3-dimensional capturing and analysis of the complete geometric structure of the inspected part. This then facilitates processes such as the analysis of faults (pores and material inclusions), material and density analysis or the examination of completeness and dimensional control (coordinate metrology) in 3D helping CT users to early detect deviations and optimize their production parameters.
In the first part of the presentation, two new CT systems specially engineered for reliable 3D statistical production process control will be compared regarding benefits for different industrial production surveillance tasks: the compact phoenix v|tome|x c high energy cone and fan beam CT scanner and the high throughput speed|scan CT 64 helix CT system (both GE Measurement & Control). The fast CT system can scan large castings like cylinderheads of approx. 500 mm in diameter x 900 mm in length within 15 seconds, with a typical scan, reconstruction and evaluation cycle speed of ~1 min. per part.
The first fast gantry based scanner (speed|scan CT 16) completely designed for industrial CT purposes has been implemented in 2013 in the process control and quality assurance concept of the Volkswagen foundry in Hannover/Germany. In our presentation we will explain the CT technology, the implementation concept, present inspection results and discuss the benefits for a foundry were daily approx. 7000 cylinderheads are being casted.

The advances in turbine engine component design, including highly complex cooling designs with advanced multi-wall castings create an inspection challenge. As an answer to the US Metals Affordability Initiative (MAI) requiring CT slices to replace ultrasonic wall thickness measurements for next generation ultra-complex aerospace turbine blades, a fully automated 450 kV X-ray CT/Metrology has been developed. Equipped with a unique high resolving fast linear detector, it allows high throughput inspection of up to 30 blades per hour by taking 10 CT slices per part for automated high precision wall thickness analyses. By generating 2D radiographic images, the system also allows easy and fast identification of critical internal structures in specific areas of interest for further verification by CT.
In our presentation we will explain the fast and efficient inspection workflow, demonstrate the productivity and repeatability gain as well as the DICONDE conform data management capabilities.
Besides this, innovative aerospace manufacturing technologies, especially additive manufacturing, allow the production of highly complex parts demanding for advanced defect and dimensional analysis tools far beyond traditional 2D radiography and conventional coordinate measurement machines. In our presentation, we will also showcase a CT study carried out on selective laser sintered TiAl6V4 part scanned with an industrial cone beam CT scanner for non-destructive porosity and inclusions analysis as well as wall thickness measurements and actual/nominal comparisons.